There's more to the performance world than buzz-box small-blocks that putt around town. For the true street heroes that dream of big-time power, the easiest way to get there is with major league cubic inches. That means big-blocks. We canvassed the big-block world and came up with seven engines, from Mopar 440s to Ford 460s, through Buick, Pontiac, and Olds 455s, a 500ci Cadillac, and of course, a 454ci big-block Chevy.
We had a simple plan-come up with a power combination for each one of these seven engines that would make a minimum of 500 hp and 500 lb-ft of torque. We will detail the carb, intake, heads, cam, compression, and exhaust components you would need to duplicate this level of power from each engine. Our goal was the mildest and least expensive combination that would make this power so that these engines could easily run on pump gas while prowling the neighborhood looking for unsuspecting prey.
So dive right into your favorite engine, but we'd suggest reading all of the engine combos. No tellin' what you might learn about these different engines and what it takes to be a 500hp Street Hero!
Pontiac 455"Five hundred horsepower? It's like falling off a log." That's how Ken Crocie from HO Enterprises described making five big ones with a pump gas 455 Pontiac. Crocie recommends not bothering with the stock Pontiac heads. He says that by the time you're done rebuilding and porting the stock iron castings, you will have invested almost as much as a set of the Edelbrock aluminum castings.
For a camshaft, Crocie recommends one of his own hydraulic flat-tappet dual-pattern cams that specs out with 234/242 degrees of duration at 0.050-inch tappet lift with 0.470/0.485-inch valve lift and a lobe separation angle of 112 degrees. With a compression ratio of 10.2:1, Crocie says this should be a very streetable combination that would be on the ragged edge of compatible with pump gas only because the shorter cam will make more midrange cylinder pressure. Crocie has seen an 80hp jump over stock Poncho castings with the Edelbrock alloy heads.
On the induction side, Crocie heartily recommends an Edelbrock RPM intake, and he prefers the Edelbrock RPM 850-cfm Q-jet but reports that a similar-sized Holley or Demon would also work very well. On the exhaust side, Crocie notes the Doug Thorley 131/44-inch headers fit the A-body GTO very well, and he'd match it up with a complete 3-inch exhaust system. This will make an easy 500 hp, and the last engine he built like this made 519 hp at 5,800 and 560 lb-ft of torque at an amazingly low 3,900 rpm. The weak links in the Pontiac 455 are the cast-iron connecting rods. If you're building a fresh engine, Crocie warns under no circumstances should you reuse the stock cast rods. Both Scat and Eagle make 4340 forged steel rods that are an excellent choice for reliability and price.
SpecsDisplacement: 455ci, bore x stroke-4.151x4.210Carburetor: 850-cfm Edelbrock Performer RPM Q-jet, PN 1910Intake: Edelbrock Performer RPM Pontiac, PN 7156Heads: Edelbrock Performer Pontiac, 87cc chamber 2.11/1.66-inch valves, PN 60579 completeCompression: 10.2:1Camshaft: HO hydraulic flat-tappet cam, PN HC02, 294/302 adv., 234/242 degrees @ 0.050, 0.470-/0.485-inch lift 112-degree lobe separationHeaders: Doug Thorley 131/44-inch primary pipeExhaust: 3-inch exhaust with DynoMax mufflers
Oldsmobile 455Dr. Olds and his fanatical followers have the luxury of the excellent 455 as a great foundation from which to build 500 hp. To get the inside scoop on what it takes to configure a pump gas 500hp street 455 Olds, we spoke to Dick Miller of Dick Miller Racing. Here's what we found out.
To begin with, Miller recommends going with an 850 HP Holley carburetor to ensure plenty of cfm to feed those hungry cylinders along with either an Offenhauser Port-O-Sonic or Edelbrock Torker single-plane intake. The single-plane might cost a little low-speed torque, but with an engine this big, you can afford to move the torque curve up a little.
The Olds cast-iron "C" heads with stock 2.07/1.71-inch valves and a 79cc combustion chamber offer the best potential. This will create around 9.75:1 compression with a typical head gasket and dished piston. Miller says you'd have to plan on substantially porting these heads to create sufficient flow to make this 500hp number, but it is possible. Another alternative is to look at the new Bulldog aluminum cylinder head that offers substantially better flow over even the ported iron heads. The heads aren't cheap at $2,195, available through Dick Miller Racing, but now you're working with a brand-new set of aluminum heads.
Miller offers his own custom cam that works very well with this combination, but he'd rather not publish its specs. A Lunati single-pattern cam that comes very close, according to Miller, offers 295 degrees of advertised duration with 245 degrees at 0.050-inch tappet lift, a valve lift of 0.569-inch, and a lobe separation angle of 108 degrees. With the Olds' long stroke, idle quality is still decent, although this should not be considered a daily driver type engine.
Miller also suggests Kooks 171/48-inch headers with 311/42-inch collectors and a 3-inch exhaust system back through Magnaflow 3-inch mufflers and 211/42-inch tailpipes. The Kooks headers offer excellent collector design and are designed to fit the popular '64-'67 Cutlass body style. According to Miller, this engine should make around 570 to 580 lb-ft of torque and 500-plus-hp without spinning the engine to extreme rpm, especially since the larger main bearings are not designed to handle high rpm.
The Olds is renowned as a torque-maker, so it's best to capitalize on those qualities.
SpecsDisplacement: 455 ci, bore x stroke-4.125x4.250Carburetor: 850 HP HolleyIntake: Offenhauser Port-O-Sonic PN 6109, Edelbrock Torker PN 7112Heads: Olds iron "C" heads, 2.07/1.71-inch valvesCompression: 9.75:1Camshaft: Lunati PN 07183 hydraulic flat-tappet 295 adv., 245 degrees @ 0.050, 0.569-inch lift 108-degree lobe separation angleHeaders: Kook's 171/48-inch primary pipeExhaust: 3-inch exhaust, Magnaflow mufflers
Chevy 454There are those who speak only in Chevy Rat motor terms when it comes to making power and torque. We talked to Super Gas racer and Flowmaster dyno master Kevin McClelland who offered his ideas on street Rat power. McClelland says the stock iron rectangle port castings can be made to work but focus on the exhaust side. The intake ports are already too big, but larger 2.250/1.880-inch valves are a good idea and pocket work will help. There are several aftermarket aluminum Rat heads to choose from, including the new 305cc AFR castings, and the 320cc World Products Jenkins signature head with 2.300-inch intake valves are excellent.
Even though this is a pump gas street engine, McClelland suggests a fast mechanical flat tappet cam with a duration of 232/240 at 0.050 with a 110-degree lobe separation angle and lift around 0.550-inch lift. Comp Cams grinds a XS268 Xtreme Energy mechanical that very closely fit this spec.
On the intake side, the Edelbrock Performer RPM Air Gap is the best choice combined with an 850-cfm Demon or Holley HP carb. Try to keep the compression under 10:1 so it will be friendly with pump gas. Kevin suggested 171/48-inch headers for peak power, or 131/44-inch headers that will help the torque. For an exhaust, a 3-inch system will make the most power, but it will also be the loudest. With that, you're ready to rumble.
SpecsDisplacement: 454ci, bore x stroke- 4.250x4.000Carburetor: 850-cfm Holley HP or Race DemonIntake: Edelbrock Performer RPM Air Gap 2-R, PN 7562Heads: Stock rectangle port iron head, World Product Merlin 310cc rectangle port iron, PN 030030-1 with 2.2.50/1.880-inch valves and 119cc chamber, or Air Flow Research Magnum 305cc aluminum heads with 2.25/1.88-inch valves and 119cc chamber, complete, PN 2100Compression: 9.5:1 (slightly higher with aluminum heads)Camshaft: Comp Cams XS268 mechanical flat-tappet cam, 268/274 adv., 230/236 degrees @ 0.050, 0.553-/0.586-inch lift 110-degree lobe separationHeaders: Hooker 131/44- or 171/48-inch primaryExhaust: 3-inch exhaust with Flowmaster mufflers
Buick 455For the port-hole performance boys, we cornered Jim Burek of Performance Auto Engineering in El Paso, Texas, to get his ideas on building a 500hp Buick 455. Burek says that it's possible to achieve 500 hp with a set of stock iron heads, but that the TA Performance Stage 1 aluminum heads are capable of that feat right out of the box. Burek says that if you clean up the ports on a stock iron head just underneath the intake and exhaust valves you can make 500 hp. However, you may have to spend significant time in order to make that goal. The easier route is with the aluminum TA Performance Stage 1 aluminum casting.
For a camshaft, Burek likes the flat-tappet hydraulics for the Buick since they are much more affordable than the rollers. In order to make 500 hp with the better cylinder heads, you'll need a cam of around 236 degrees at 0.050-inch tappet lift with 248 or so on the exhaust side with a 110-degree lobe separation angle. This will create enough power to get the Buick going without spinning it very fast. On the exhaust side, Burek prefers the 171/48-inch headers and he prefers the X-pipe crossovers over the H-pipes, unless the engine is very mild.
The weak link with the Buick is its small area cam bearings that burn up easily. With a big cam and higher valve spring pressures, go with the back-grooved bearings that will prevent roasting the bearings. The other weakness is the block. Above 600 hp, the crank literally pushes the main webs right out of the block! The ultimate fix is a new iron block from Bulldog that will sell for around $3,600 but will offer over 1,000hp durability.
SpecsDisplacement: 455ci, bore x stroke-4.3125 x 3.90 inchesCarburetor: 750- to 850-cfm Speed DemonIntake: Edelbrock Performer, PN 2146Heads: TA Performance Stage 1 alum., 2.125/1.750-inch valvesCompression: 10:1Camshaft: 236/248 @ 0.050 flat tappet hyd. 0.500/0.520-inch liftHeaders: 171/48-inch full lengthExhaust: 3-inch w/X-pipe
Ford 460When it came time to determine a 500hp street package for the 460 Ford, we found an excellent combination in the Ford Racing catalog with the 460ci Super Cobra Jet crate engine. Ford rates this complete engine system at 500 hp and 495 lb-ft of torque. This is based on a custom-built, 0.030-over remanufactured block spinning all-new rotating pieces.
If you want to build your own, the combo is built around noted Ford engine-builder Jon Kaase's Super Cobra Jet aluminum heads that offer outstanding 330-cfm intake and 225-cfm exhaust flow numbers from a set of heads that use similar components to the previous Ford 429 Super Cobra Jet head. The valve angles have changed, so you may have to cut new notches in existing pistons. These heads will also require new pushrods and guideplates.
The cam for this package is a Ford Racing hydraulic flat-tappet with a relatively mild duration yet still cranking out over 0.550-inch lift. Induction duties are assigned to an Edelbrock Performer RPM 460 dual-plane and, like all the other engines, an 850-cfm carb will probably perform the best. On the exhaust side, a set of 131/44-inch headers may not look racy, but they will contribute to increased torque. They'll more likely fit better in the tight Ford engine compartment as well.
SpecsDisplacement: 460ci, bore x stroke-4.360x3.850Carburetor: 850-cfm Holley HP or DemonIntake: Edelbrock Performer RPM, PN 7166Heads: Ford Racing Super Cobra Jet aluminum head, 2.200/1.76-inch valves, 72cc chamber, 290cc intake volume, PN M-6049-SCJA (assembled)Compression: 10.5:1Camshaft: Ford Racing hydraulic flat-tappet cam, 300/310 adv., 234/244 degrees @ 0.050, 0.562-/0.588-inch lift, PN M-6250-A443Headers: Hooker 131/44-inch primary pipeExhaust: 3-inch exhaust with Borla mufflers
Chrysler 440There are many acknowledged Chrysler wedge engine-builders, but few with Dick Landy Industries' (DLI) Mopar engine-building experience. According to Landy, you can make 500 hp with a 0.030-over 10:1 compression raised block (RB) 440 using heavily ported 906 iron production cylinder heads, but this requires a tremendous amount of work and no guarantee of reasonable durability. A lightweight alternative is the Mopar Performance aluminum Stage VI heads. With larger 2.14/1.81-inch valves and excellent flow potential, you can easily crank out another 50 hp with these heads over the stock iron castings.
Because the heads flow so well, Landy suggested a reasonable DLI hydraulic flat-tappet cam with 280/290 degrees of advertised duration along with 0.480-/0.502-inch lift and a 108-degree lobe separation angle. The Stage VI heads required the Mopar Performance Stage VI single-plane intake matched up with an 850-cfm Holley carburetor. Combine that with a set of 2-inch Hooker headers and a 3-inch exhaust, and you have what it takes to make well over 500 hp.
SpecsDisplacement: 440 ci, bore x stroke-4.320x3.750Carburetor: 850-cfm Holley HP, PN 0-4781C Intake: Mopar Performance Stage VI, PN P5249358Heads: Mopar Performance Stage VI, PN P4876311Compression: 10.5:1Camshaft: DLI 280/290 degrees advertised, 0.480-/0.502-inch lift w/108-degree lobe separation angleHeaders: 2-inch primary pipe Hooker headersExhaust: 3-inch exhaust with Hooker mufflers
Cadillac 500ciThe Caddy is by far the biggest of our street heroes, but also affords Cadillac fanatics the easiest task to make the five-bill mark. Richard Potter of Cadillac Performance Parts in Soddly-Daisy, Tennessee, gave us a quick power tour.
Potter says that the Cadillac production iron heads have enough potential that with two days' worth of grinding, you can port a set of 902, 250, or 950 casting number Cadillac heads to raise the port flow up to 500hp levels. The heads have a high nickel content so they're hard, which is why it takes so much time. He also adds 2.190/1.840-inch valves (2.000/1.625-inch are stock). With the small 76cc chamber, the engines need a big dish for the 0.060-over piston to get the compression around 10:1 to run on pump gas.
Potter prefers to spec his own custom cams that Comp Cams grinds for him. Because the engine is so big, it can handle a flat-tappet hydraulic cam with 255/245 degrees of duration at 0.050-inch tappet lift with 0.550 to 0.560-inch valve lift. Note that the exhaust duration is shorter than the intake. Potter says the exhaust is so good, he prefers less duration on the exhaust side.
For a street engine, Potter says the Edelbrock Performer intake works best, but it will max out at around 5,000 to 5,200 rpm. He offers a Dominator style intake, but it's too big for the street. For carburetors, it's tough to beat the 800-cfm stock Q-jet for driveability, but he also likes the 850-cfm Holley HP carb for all-out power. As for exhaust, Sanderson makes a block-hugger 171/48-inch header that seems to work well, but this will depend upon the body application, especially if you're planning on an engine swap like a 500ci Cad into a '55 Chevy or a Henry J.
The Cad does have two weak spots. According to Potter, the valvetrain is "worthless," and he recommends his Cadillac Performance rocker arms. The other area is the stock cast-iron connecting rods. Potter prefers to use Oldsmobile-forged rods that are only slightly shorter. Other than that, Potter says the nodular crank can handle the easy 550 hp this combination can grunt out.
SpecsDisplacement: 500ci, bore x stroke-4.300x4.304Carburetor: 850-cfm Holley HP, Race Demon, 800-cfm Q-jetIntake: Edelbrock Performer, PN 2115Heads: Stock 950 cast-iron heads, heavily ported 2.190/1.840-inch valvesCompression: 10.2:1Camshaft: Comp Cams, custom-grind hydraulic flat-tappet 255/245 degrees @ 0.050, 0.550-/0.550-inch lift, 110-degree lobe separationHeaders: Sanderson 171/48-inch primary pipeExhaust: 3-inch exhaust with DynoMax mufflers
Holley Performance Products (Lunati)
1801 Russellville Rd.
P.O. Box 10360
Dick Landy Industries
19743 Bahama St.
Mopar Performance Parts
AirFlow Research (AFR)
28611 W. Industry Dr.
Dick Miller Racing
Ford Racing Performance Parts
44050 N. Groesbeck Hwy.
Demon Carburetion/Barry Grant
16167 N. 81st St.
2700 California St.
Kooks Custom Headers
Performance Automotive Engines (PAE)
Cadillac Performance Parts